RF3:GTP promotes rapid dissociation of the class 1 termination factor

Measurements of the dissociation of mant-nucleotides from RF3. The rate of (A) mant-GDP and (B) mant-GTP dissociation from RF3 was monitored by stopped-flow fluorescence upon the addition of a nonlabeled nucleotide (GDP or GTP) chase. The data were fit to a single phase, and the fit is displayed as a white line. The rates of nucleotide release from RF3 were slow (k_{off, mantGDP} = 0.005 sec⁻¹, k_{off, mantGTP}= 0.01 sec⁻¹).